Electrical boxes are used in building construction for enclosing electrical components such as switches, outlets, and electrical appliance connections. The electrical box is generally secured to studs or joists in a wall, ceiling, or floor construction with an open front or face of the electrical box facing toward an interior of a room. When an electrical box is utilized, a vapor barrier provided by the wall to prevent cold winter air from entering into a structure or building through the wall must be at least partially penetrated by the mounting of the box. Therefore, it is highly desirable to provide a new and improved electrical box, which allows the box to be installed in a wall, while maintaining an integrity of the vapor barrier of the wall.
One method of providing a vapor barrier in external walls and ceilings of a building is to provide a vapor seal comprising a continuous plastic sheet between the studs and the drywall of the building. The vapor seal forms an entirely encompassing vapor barrier around an exterior wall of the building to prevent undesired leakage of air into or out of the building. The use of the electrical box requires penetration of the vapor seal, as well as the layers of drywall provided adjacent the vapor seal. Heretofore, it is extremely difficult to provide a vapor seal between the electrical box and the drywall to maintain the integrity of the vapor barrier. Therefore, it is highly desirable to provide a new and improved electrical box that can provide the vapor seal at the vapor barrier of the exterior wall or the ceiling to maintain the integrity of the vapor barrier.
In many circumstances, the electrical box is installed into an existing wall structure wherein components such as the joists, the studs, the vapor seal, and the layers of drywall are already installed. Electrical boxes used for such applications are typically referred to as “old work” electrical boxes. The introduction of the new electrical box typically requires portions of the wall or ceiling construction, including the drywall and potentially a portion of the vapor seal, to be penetrated and subsequently removed to form an opening having a shape and size corresponding to a shape and size of a periphery of the electrical box. One or more gaps may be created about the periphery of the electrical box if such an opening does not correspond precisely to the shape and size of the periphery of the electrical box. Thus, air may flow between a space in the wall or the ceiling present outboard of the vapor barrier and an interior of the room requiring the opening, thereby reducing a thermal efficiency of the wall or the ceiling.
It is desirable to provide a new and improved electrical box that not only can be mounted in a manner to maintain the integrity of a vapor barrier in an exterior wall or ceiling of a building, but which also accommodates any small inconsistencies in dimensions, alignment, and the like of the electrical box within the wall structure, allowing fast and efficient construction, while at the same time maintaining a vapor seal about a periphery of the electrical box.